feat(i18n): remaining German comments + CI strings in English

Final residual translations found in code/comments/CI:
- .doorstop.yml: config comments, traceability mapping comments
- Doxyfile: header comment
- tools/render_plantuml.py: docstring
- tools/generate_test_report.py: docstring
- tests/unit_test_framework.h: doxygen brief + body
- tests/unit/test_safety_manager.c: section comment
- src/stubs/*.h: doxygen briefs for diag/display/inclinometer/logger/service/wheel-speed
- .gitea/workflows/release.yml: release notes 'Statische Analyse' + deploy error message

tests/unit_test_framework.h

@@ -1,10 +1,10 @@
 /**
  * @file unit_test_framework.h
- * @brief Minimaler Test-Runner fuer demo-epb.
+ * @brief Minimal test runner for demo-epb.
  *
- * In Produktion wuerde hier CppUTest oder Google Test stehen
- * (siehe docs/SWE-Plan.docx, Abschnitt 7). Fuer die Demo
- * bleibt das Framework klein, damit es ohne externe Abhaengigkeiten baut.
+ * In production CppUTest or Google Test would go here
+ * (see docs/SWE-Plan.docx, section 7). For the demo, the framework
+ * stays small so it builds without external dependencies.
  */
 #ifndef UNIT_TEST_FRAMEWORK_H
 #define UNIT_TEST_FRAMEWORK_H